I cant help but think the scientology building took advantage of being close to a CEX, something like "who is xenu?" Suddenly appearing on the shelves. At least you get movie and dinner with that setup though, dates made easy by the Cap'n!Curiously the CeX in Tottenhan Court Road in Central London (situated next to a Scientology building and a KFC) used to have straight up pornographic content (some did have BBFC logos so assumed legal) situated on a shelf in the basement above the rest of the DVDs.
The basement used to have a metallic, slightly dingy feel to it too but has recently been renovated and said iffy DVDs are now nowhere to be found. I’ve yet to see any hentai DVDs though.
As for @NormanicGrav 's thing, remember when some of those were out the BBFC wanted to cut a tonne of questionable content, some down to nothing. Not much chance anyone wanted to put something cut that much on the shelves, so UK boxart wasnt really worth doing. Perhaps someone on the forums feelin' a little cheeky may give us the idea of what that boxart might have looked like...